Furnace bonnet



Feb. 1,1927. 1,615,888

A. G. SCHERER FURNACE BONNET Filed June 9, 1926 jaentob erably inclined.

l atented Feb. 1, 1927.

onirsn stares n rel c E rarsnr ALBERT G. SGHERER, OF CHICAGO, ILLINOIS, ASSIGNOR TO THE EXOELSIOR STEEL FURNACE COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

FURNACE BONNET.

Application filed June 9,

My present invention relates to improvements in bonnets for furnace casings.

As is well known, in hot air furnaces, the heating element is enclosed in a casing through which the air to be heated is circulated. The top section of such a casing is known as a bonnet and it is with this bonnet that connection is made with the pipes for the delivery of hot air to the locations where it is desired.

It is desirable, if possible, to have the pipes connecting with the bonnet run upwardly to facilitate the flow of the lighter hot air and, for this reason, the side of the bonnet is pref- And, for the same reason, the top of the bonnet is preferably made of an inverted pyramidal form so that there will not be any dead or even eddy space in the center of the bonnet. The inwardly inclined sides and the inverted pyramidal form of the top of the bonnet, desirable for i110- proving the circulation of the hot air, tends somewhat to weaken the structure against outward compression and my present design is intended to overcome this weakening tendency as well as to increase the area of lateral wall available for connection with hot air discharge pipes and also to refine and improve the appearance and structure of furnace bonnets.

I attain the foregoing objects by means of the structure illustrated in the accompanying drawing in which Fig. 1 is an elevation of a furnace bonnet embodying my invention;

Fig. 2 is a central, vertical transverse section of the structure shown in Fig. 1; and

Fig. 3 is a fragmental sectional detail of the assembly of the top and side of the bonnet.

Similar reference characters refer to similar parts throughout the several views.

I have omitted a description of the furnace casing as a whole as such structures, while differing considerably from each other, are similar in constituting a cylinder with which the bonnet, or top section, assembles.

My improved bonnet comprises the lateral wall 4, which is outwardly beaded at 5 a suitable distance above its lower edge, the

1926. Serial No. 114,613.

space between the bead 5 and the lower edge being crimped as at 6 to provide a slight taper to secure a tight and substantial assembly with the body of thecasing. Above the bead 5 the side wall preferably inclines towards the center of the structure so as to facilitate an upward inclination of the con nected piping, an opening for which is indicated by dotted line 7. As the divers premises to be'heated are hardly ever similar, the number and locations of these openings should be made with special reference to the particular location where apparatus is to be installed.

The top of the bonnet is preferably of inverted pyramidal form and the means of assembly between the side and the top is of particular significance in the present structure. To make this assembly I bend or form the upper edge of the side wall inwardly in a substantially horizontal direction, as at 9, and then backwardly upon itself, as at 10. The outer edge of the top is provided with a vertical shoulder as at 11, and is the-n eX- tencled outwardly and horizontally as at 12,

and then backwardly between the folds 9 and 10 of the side wall, as at 13.

As will be clearly seen this construction provides a four thickness reinforcement disposed edgewise, that is, in the direction of its greatest strength, against the collapsing of either the side or top of the'bonnet.

Further, this construction is economically made and is capable of much more accurate and neat fabrication than the conventional double seaming. The shoulder 11, as well as the friction between the engaging surfaces, prevents the side wall from being driven inwardly out of assembly and the hook formed by the portions 12 and 13 secures the top against a like contingency.

Having described my invention what I claim as new and desire to secure by Letters Patent is 1. A furnace bonnet comprising a side wall and a circular top wall reinforced by a continuous ring extended horizontally and located immediately over the top of the side wall and extending inwardly therefrom and formed by the engagement of said bonnet ion Walls in elongated opposite reverse bends and a shoulder extending outwardly from said top and abutting the bend in said side.

2. A furnace bonnet comprising an upwardly, inwardly inclined side Wall and an inverted conical top wall engaging in oppositely, horizontally disposed, elongated reverse bends and a shoulder provided in said top abutting said reverse bends, Whereby a continuous, flattened, reinforcing ring 10 is provided against the collapsing of said side and top Walls.

ALBERT G. SOHERER. 

